Fabrication of semiconductor devices includes performing various fabrication processes on a semiconductor substrate configured as a semiconductor wafer or other bulk semiconductor substrate. For example, different electrically insulative materials and electrically conductive materials may be formed over a semiconductor substrate. The electrically insulative materials and the electrically conductive materials are patterned to form features of the semiconductor device, such as individual memory cells, transistors, capacitors, electrodes, conductive vias, or other features.
Patterning of the materials of the semiconductor device may include exposing one or more materials to a material removal process, such as an etching process. Etching processes may include, for example, a wet etching process or a dry etching process. Wet etching includes exposing the semiconductor device to a solution formulated to remove at least a portion of one or more materials of the semiconductor device. The semiconductor device may be exposed to the wet etchant by immersing the semiconductor device in the etchant, spraying the etchant onto the device, or another method.
Dry etching is another method of patterning a semiconductor device. Dry etching may include plasma etching, reactive ion etching (RIE), ion beam etching, or combinations thereof. Dry etching conventionally includes exposing the semiconductor device to a plasma formulated and configured to remove one or more materials of the semiconductor device therefrom. In a conventional dry etching process, reactive species in the plasma react with the material being removed to form a gaseous product, that may be carried out of the etch chamber under etching conditions (e.g., proper temperature, low pressure conditions, etc.). Depending on the materials being removed and the plasma used during the dry etching process, solid byproducts may be formed. In some instances, the byproducts include polymers, salts, or other materials that are not substantially removed from the etch chamber under the conditions of the dry etch process. The polymers, salts, or other materials may form deposits on walls and other surfaces of the etch chamber.
In some instances, the deposits may be electrically conductive, such as when the deposits comprise salts or a conductive polymer. In some such instances, electric charges may accumulate on the conductive deposits and may form an electric potential. If sufficient charge accumulates on the electrically conductive deposits, an arc may form between the deposits and the semiconductor substrate being processed. Such arcing may damage (e.g., break) the semiconductor substrate and may cause the semiconductor devices on the semiconductor substrate to fail.
Accordingly, after a certain number of wafers have been processed, the etch chamber may be cleaned to remove deposits therefrom. However, cleaning the etch tool may reduce the amount of time that the etch tool may be used for patterning semiconductor devices and may consequently undesirably reduce a throughput of the etch tool.